// This program takes in a string, and a substring and then
// searches the main string for the occurence of the substring

// Week 4 Lecture 8

#include <stdio.h>
#include <string.h>

// Define the size of the array = this is clearly going to cause some
// waste - one of the downfalls of arrays
#define MAX_LENGTH 124

int main(void) {

    // Declare our array to hold the string
    char string[MAX_LENGTH];
    char substring[MAX_LENGTH];
    
    printf("Type in a string: ");
    // Read in the string using fgets() function
    fgets(string, MAX_LENGTH, stdin);

    printf("Type in a substring: ");
    // Read in the string using fgets() function
    fgets(substring, MAX_LENGTH, stdin);

    // Do some magic here to search:
    // How do we search through the main word? Do we do it all at
    // once or does it have to be character by character?
    // What would be the logic here?
    int main_len = strlen(string);
    int substring_len = strlen(substring);
    int flag = 1;
    // Check if the substring exists in the main string
    for (int i = 0; i <= main_len - substring_len; i++) {
        for (int j = i; j < i + substring_len; j++) {
            // Initialize the flag for matching substring
            flag = 1; 
            if (string[j] != substring[j - i]) {
                flag = 0; // Set the flag to zero if characters don't match
            }
        }
    }

    if (flag == 1) {
        printf("The substring exists in the string.\n\n"); // Display message if the substring is found
    } else {
        printf("The substring does not exist in the string.\n\n"); // Display message if the substring is not found
		
		return 0; // Return 0 to indicate successful execution of the program
    }

    return 0;
}